Effectiveness of non-exchangeable potassium quantified by mild tetraphenylboron extraction in estimating radiocesium transfer to soybean in Fukushima.
Sci Total Environ
; 820: 153119, 2022 May 10.
Article
in En
| MEDLINE
| ID: mdl-35041960
ABSTRACT
Non-exchangeable K released from soil minerals can reduce radiocesium transfer to plants, as well as exchangeable K. We investigated the effect of non-exchangeable K on radiocesium transfer to soybean, and the non-exchangeable K extraction method most suitable for estimating the transfer risk. In Fukushima Prefecture, Japan, 106 soils were collected from 89 soybean fields during 2014-2018 to analyze non-exchangeable K contents using three methods:
boiling nitric acid extraction, tetraphenylboron extraction, and mild tetraphenylboron extraction. The non-exchangeable K contents quantified by the former two methods were dependent on the amount of micas, which are K-bearing minerals. The non-exchangeable K content by mild tetraphenylboron extraction depended on the amount of K fertilizer application and K-fixing minerals but not on micas, indicating that it reflects fertilizer K fixed by the minerals. The soil-to-plant transfer factor of radiocesium was most correlated with the non-exchangeable K content by the mild extraction (rs = -0.67). This correlation was also stronger than that between exchangeable K and the transfer factor (rs = -0.40). As non-exchangeable K content increased, the exchangeable radiocesium fraction decreased, indicating that radiocesium was fixed together with K. Additionally, multiple regression analysis indicated that non-exchangeable K by the mild extraction significantly decreased the transfer factor even if the exchangeable radiocesium fraction was kept constant. Thus, the fixed K was considered to repress radiocesium transfer to soybean through both radiocesium fixation and K supply. With the criterion of total extracted K, the sum of exchangeable and non-exchangeable K, as 65 mg K2O 100 g-1 by the mild extraction, fields with high and low transfer factors were able to be differentiated more effectively than with a current criterion of exchangeable K as 50 mg K2O 100 g-1. The results revealed that mild tetraphenylboron extraction is effective for estimating radiocesium transfer to soybean.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Soil Pollutants, Radioactive
/
Radiation Monitoring
/
Fukushima Nuclear Accident
Country/Region as subject:
Asia
Language:
En
Journal:
Sci Total Environ
Year:
2022
Document type:
Article